What is the surface area of 8mm 9mm 10mm

How do you know?

I do not even know what the shape is!

easy

8*9*2=144

9*10*2=180

10*8*2 =160

then you add it all up

which equals:

484

overall, the surface area is 484 mm squared

484 add the areas of each surace(aka face of the 3d shape) and u get 484